| The present paper deals with the population dynamics of grasshoppers on alpine prairie Xiahe county, Gansu Province. The results are as follows:(1) The kind composition of grasshoppers are distinct notolike. Size of similarty-index and degree of presence for grasshoppers on different habitats are outcome, which are grasshoppers adaptation to living environment. Approach distribution area for similarty-index of grasshoppers, degree of presence of habitats types are raise.(2) Based on data from investigation on different habitats, the area and the period occurrence of principal grasshoppers species have been ascertained.(3) The mathematical model in time sequence of population dynamics of Myrmeleotettix palpalis, Chorthipp dubius, Ch .albommus, Angaracris spp and mixed population where produced with pionomic mathematics methods were reflected very occurrence condition of grasshoppers grassland. The mathematical models are as follows:(4) Based on equation m = + m + m2, distribution model of nymphs and adult grasshoppers were established, dynamic in time sequence of gatheringdegree(m/ m) for theirs were analyzed. The distribution model of mathematical models are as follows :m =-0.20649 + 1.46888m-0.16018m2, r=0.98620**;m* =0.68449-0.01538m + 0.14264m2, r=0.93266**.(5) Based on investigetion date, the theory sampling of grasshopper mixed population was researched. The theory sampling numbers are 20-40 specimen in forecast and control.
|
PDF Full Text Request